From: Cliff Wickman <cpw@xxxxxxx>
Because addresses of each successive page structure are often descending
it is much faster to use read()'s, so set off info->flag_usemmap
while doing exclude_free_page().
Signed-off-by: Cliff Wickman <cpw at sgi.com>
---
makedumpfile.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)
Index: makedumpfile.mmap/makedumpfile.c
===================================================================
--- makedumpfile.mmap.orig/makedumpfile.c
+++ makedumpfile.mmap/makedumpfile.c
@@ -3925,9 +3925,18 @@ _exclude_free_page(void)
return TRUE;
}
+/*
+ * Note that this is a very lengthy process, even using mmap(2). The
+ * page structures in the free lists are read one-at-a-time, but using
+ * readpage_elf(), which reads an entire page. And addresses of each
+ * successive page structure are often descending, which means that each
+ * read is another mmap(2) operation.
+ * It is much faster to use read()'s, so set off info->flag_usemmap here.
+ */
int
exclude_free_page(void)
{
+ int save = info->flag_usemmap;
/*
* Check having necessary information.
*/
@@ -3961,8 +3970,12 @@ exclude_free_page(void)
/*
* Detect free pages and update 2nd-bitmap.
*/
- if (!_exclude_free_page())
+ info->flag_usemmap = 0;
+ if (!_exclude_free_page()) {
+ info->flag_usemmap = save;
return FALSE;
+ }
+ info->flag_usemmap = save;
return TRUE;
}
